Receiver for telephones.



No. 884,235. PATENTED APR. '7, 1908. L. STEINBERGEB.

RECEIVER FOB. TELEPHONES. APPLICATION FILED PEB. 1s, 1907.

A TTUHNE YS LOUIS STEINBERGER, OF NEW YORK, N. Y.

RECEIVER Foa TLEPHoNEs.

Specication. of Letters Patent.

Patented Appl 7, 190s.

Application filed February 18, 1907.` Serial No. 357,881.

To all 'whom 'it 'may concern:

Be it known that I, LoUrs STEINBERGER, a citizen of the United States,and a resident of the city of New York, borou h of Brooklyn, in thecounty of Kings and tate of New York, have invented a new and Im rovedReceiver forTelephones, of which the ollowi is a full, clear, and exactdescription.

A Iy invention relates to receivers for telephones, my several objectsbeing as follows:

I. To provide the receiver with a self-locking cap which can notordinarily be vmoved without taking the receiver apart;

II. To provide the receiver with resonating chambers of peculiarconformity for the pur ose of improving the acoustic qualities oft esounds;

III. To distribute the magnets to better advantage relatively tol thecenter of the vibratory diaphragm of the receiver;

IV. To provide the receiver with a compound magnet of approvedconstruction/for drawing the diaphragm;

V. To provide a receiver casing of such conformity as to reduce the'danger of breakingthe receiver cap. v

I. To hold the receiver casing in position by the locking member whichserves also as a guide for the conductors, and VII to embed a portion ofthe magnets and wires with a core of insulating material.

Reference is to be had to the accompany.- ing drawings formin a part ofthis specification, in which simi ar characters of reference indicatecorresponding parts in all the figures. l

Figure 1 is a central longitudinal section through a receiver made innaccordance with my lnvention; Fig. 2 isv a vertical section upon theline 2-2 of Fig. 1 looking in thev ldlrection of the arrow, and showingthe position of the resonance chamber, the electromagnets mountedtherein, and a portion ofthe self-locking cap and parts connectedtherewith; Fig. 3 is a fragmentary elevation of the compound magnetshowing how it is built up v of single magnets connected t0- .gethenFig.v 4 is a side elevation partly broken away, and showing the cathreaded both internally and externally. p

Two ermanent magnets 4, 5, of the -socalled i orseshoe type, areconnected together by a rivet 6 and thps'formed into a compound magnet.A number .of pole pieces 7, corresponding to the number of magnet poles,are mounted upon the latter,

embedded wit the several pole pieces being provided with a roundedportion 8, 10, 11, 12, these portions being encircled by cylindricalspools 9 of magnet'wire. The compound magnet is partially embeddedwithin a core 13 of insulating material, referably Electrose Also hinthis material are electrodes 14 provided at one end with binding posts15, 16. Conducting wires are shown at 17, 18. A locking member is shownat 19 and is provided with a compartment 20 and with a centrallydisposed aperture 21. This locking member is mounted upon a threadedportion 22 ofthe core 13 and at'this end is threaded internally at 23. Ametallic case 24 is provided with an enlarged and thickened portion 25,the latter being provided at 26 with a thread. This enlarged andthickened portion 25 is rounded off at 27. other Words, the/generaldiameter of the portion 25 is less at the point 27 than is the genveralequatorial diameter of this portion.

The core 13 is provided with a resonating chamber 28 having an enlargedportion 2 9, the portion 28 being rounded at one of lts ends, and at itsother`1nerging into the porl tion 29. The core 13 is provided at one ofits ends With an annular portion 30 integral therewith and threadedexternally. Adjacent to this threaded annular portion the 'core 13 isalso provided with an annular shoulder 31. The thread of the portion 30is of a different pitch than the thread 26, for a purpose hereinafterstated. A cap 32, of

,insulating material, is provided With an annular shoulder 33 adapted toabut against the annular shoulder 27 ofthe metallic portion 25. The fitof the cap relatively to the shoulder 27 is such that when the cap isfirmly in position, .there is no noticeable seam between these twoparts. AThe cap 32 is provided with an 'annular portion l34: threadedboth externally and internally. Its

external thread fits into the thread 26, whiled its internal thread fitsthe thread 30. Since, however, the external and internal threadsl of theannular portion 34 of the cap, are of different pitch, any effort toturn the cap causes it to lock relatively to these portions, providedboth. of themare in engagement with it. .The diaphragm is shown at 35and is of a diameter approximating the internal diameter of the annularportion 34.

. The several arts above described are assembled as fo ows: During theprocess of manufacture the compound magnet is mount- -von afterward.Suppose, now, we have a corecom`ple`te with its permanent and itselectro ma nets. We rest the diaphragm 35 upon the arge end of the coreand then screw the cap 32 into position. The annular' portion 34 of thecap now encircles the thread portion 30 of the core and also engagesth(l annular shoulder 31, so that the annular edge of the diaphragm isclamped iirmly between the cap 32 and a part of the core 13. The

metallic casing 24 is now slipped over the 'core 13 from the smaller endt '1ere-of and isv turned so that the threaded portion 26 of the core isfitted into the corresponding threaded portion of the cap 32. vTherotation of the casing is continued until the shoulder 27 jams firmlyagainst the shoulder 33 of the cap. The locking member 19 is now screwedupon the smaller end ofthe core and brought into rrn engagementwith thesmall end of the casing 24. The wires 17, 18 having been previouslyconnected with the binding posts 15, `16 and threaded through thelaperture 21, the tightening of the locking member 19 leaves thetelephone receiver complete and ready .for use. It will now be foundthat a person is unable to remove the cap' 32 by merely turning itrelatively to other parts. This is because, owing to the differentialpitch of the threads disposed internally and externally of the cap, theinstant the latter begins to turn, the locking action above describedensues, and it is therefore impossible,

under the circumstances, Yto remove, or even to displace, the cap'. Inorder to remove the cap the locking member 19 is unscrewed and shpped tothe right, according to Fig. 1. The easing 24 is next unscrewed andmoved also to the right. readily unsorewed from its fastenings andremoved in like manner as any other cap used u on a receiver. My purposein giving the lt lekened portion 25 of the casing 24 a smaller diameterat the point 27 than at other points, 1s to cause the receiver to strikeupon the rounded portion27 in case the re-4 ceiver is caused to swinglaterally and to strike an obstruction, such as a Wall. ln other Words,according to the view shown in Fig. 1, the portion 25 is extended alittle toward the left and isslightly rounded at its end so that, if thereceiver should swing and strike an obstacle, the force should bereceived upon the portion 25 rather than upon the cap 32. y

As will be understood from Figs. 1 2, the pole pieces 8, 11 are ofopposite polarity; the pole ieces 10, 12 are also of opposite'polarlcting, however, upon a soft 1r on diep agm, or other non-polarizeddlaphl'agm, the magnets, independently of their The cap 32 may new be'poles of the 'electromagneta and they may with a thread mating olarity,will all pull' in the same direction.

lence, the attraction of theldiaphragm by a group of magnets isequivalent to the cornbined pulling power of all' of"the magnets. Theelectromagnets are equidistant from the center ofthe diaphragm and maybe consid-` ered as approximating a circle concentric to the center ofthe diaphragm. Owing to this arrangement it is not necessary toilattenthe readily be made cylindrical, as shown.

l have found that it is practicableto make the resonating chamber-28ofvsuch length, measured from the diaphragm to the most remote part ofthe reson nce chamber, that the sounds, when made by the diaphragm andrellccted fromA the bottom of the reso# nance chamber, are reinforcedupon again reaching the diaphragm. ln other words, the shape of theresonance chamber serves to correctly focus the sounds upon thediaphragm and, as nearly as practicable, upon the center thereof. Theenlarged portion 29 of the resonance chamber acts in the manner of amouthpiece in guiding the sound towardthe rear end of the chamber.resonance chamber the quality of-the tones of a voice is greatlyimproved and the loudness of the sounds is increased. The quantity ofwire required in the spools isless than would be the case if the polepieces and spools were flattened. f

I do not limit myself toany particular ma- 'terials to be used 1n theconstruction of this receiver, neither do I myself to the shape or form,of any part or to any combination of parts, except as' such isdetermined by the language of my claims. Y I

Having thus described' my invention, I claim as new and desire to secureby Letters Patent:

1. A telephone receiver comprising a core provided with an annularthreaded'portio'n integral therewith, a diaphragm having an annular edgedisposed ad] acent to said annular threaded portion, a cap screwed uponsaid threaded portion and encircling said diaphragm, and a casingpartiallyeneircling said core' and said cap for'the p ose of preventingrelative movement there tween.

2. The combination with a core vprovided with a thread, a cap providedwith a thread engaging said thread of said core, said cap being providedwith a second thread ha a pitc different from said irstfmentione threadof said cap, and a casingkprovided' said second-mentioned thread of saidcap.

,llt

3. A telephone receiver, comprising tially cylindrical portion ofsmaller diameter, said portions merging together, said smaller portionbeing provided with a concave end for the purpose of concentrating andretlectf ing sound waves, magnetic mechanism mounted within said portionof larger diameter, a diaphragm disposed adjacent to said ma neticmechanism, and means for holding sai diaphragm in position.

4. The combinatlon of a hollow casing provided at one of its ends with athread disposed internally thereof, a core of insulating materialprovided with a neck having a 'thread disposed externally thereof, saidthread of said neck being of a different pitch from said thread of saidcasing, and a cap of insulating material provided internally with athread mating said thread of said neck, and said cap being providedexternally with a thread mating said thread of said casing.

5.- In a telephone receiver, thecombination of a metallic casingprovided internally at one of its ends with a thread, a core ofinsulating material mounted within said metallic casing and providedWith a neck, said neck having' upon its exterior a thread, said neckbeing shorter than the threaded portion of said casing, a cap ofinsulating material provided externally with a thread mating said threadof said casing and provided internally with a thread mating said threadof said neck, and means coacting With said cap for preventing relativemovement between said casing and said core.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

LOUIS STEIN BERGER.

